Robotic and clinical evaluation of upper limb motor performance in patients with Friedreich’s Ataxia: an observational study

Table 5 Correlation coefficients among the robotic indices for patients with FRDA

	Duration of movement	Mean velocity	Peak velocity	Length ratio	Lateral deviation	Aiming angle	Normalized jerk	Speed metric	Number of submovements	Duration of submovements	Amplitude of submovements
Duration of movement	1	−0.793**	−0.741**	0.771**	0.323	0.200	0.960**	−0.604*	0.947**	0.099	−0.758**
Mean velocity	−0.793**	1	0.965**	−0.327	0.033	0.029	−0.837**	0.182	−0.802**	−0.182	0.978**
Peak velocity	−0.741**	0.965**	1	−0.297	0.112	0.187	−0.789**	0.108	−0.754**	−0.138	0.969**
Length ratio	0.771**	−0.327	−0.297	1	0.644*	0.376	0.714*	−0.802**	0.754**	−0.231	−0.310
Lateral deviation	0.323	0.033	0.112	0.644*	1	0.697*	0.367	−0.618*	0.358	−0.385	0.099
Aiming angle	0.200	0.029	0.187	0.376	0.697*	1	0.226	−0.248	0.270	0.007	0.086
Normalized jerk	0.960**	−0.837**	−0.789**	0.714*	0.367	0.226	1	−0.547	0.974**	−0.059	−0.820**
Speed metric	−0.604*	0.182	0.108	−0.802**	−0.618*	−0.248	−0.547	1	−0.556	0.305	0.125
Number of submovements	0.947**	−0.802**	−0.754**	0.754**	0.358	0.270	0.974**	−0.556	1	−0.077	−0.807**
Duration of submovements	0.099	−0.182	−0.138	−0.231	−0.385	0.007	−0.059	0.305	−0.077	1	−0.103
Amplitude of submovements	−0.758**	0.978**	0.969**	−0.310	0.099	0.086	−0.820**	0.125	−0.807**	−0.103	1

Spearman’s rank correlation coefficient are reported. The symbol * indicates a statistical significance, with p < 0.05; the symbol ** indicates a statistical significance, with p < 0.01 (p values are corrected for multiple comparison, by using a False Discovery Rate procedure).

ISSN: 1743-0003